Every once and awhile, while teaching or going through my image collection, I’ll come across something and I’ll think: ‘that should be on the blog’. So here’s a recent one, a detail from the early 13th century mosaic of the Deisis in Hagia Sophia, of St John the Baptist. The subtlety in the range of colour and use of the tesserae (the little bits the mosaic is made up of) is really remarkable. I can’t wait to get back to Istanbul. Maybe 2019.